Well packers and control line management

ABSTRACT

An example of a wellbore tool assembly includes a mandrel having an outer surface and a longitudinal bore; a tubular, swellable seal member having opposing ends and an inner surface defining a bore between the opposing ends, the seal member encircling a portion of the mandrel; an operable downhole element carried with the mandrel; and a control line connected to the operable downhole element, the control line extending from the downhole element between the outer surface of the mandrel and the inner surface of the seal member to the other side of the seal member from the downhole element.

TECHNICAL FIELD

The present invention relates in general to wellbore packers and morespecifically to extending a conduit, control line or the like past awell packer that is set in a wellbore.

BACKGROUND

It is often necessary to utilize a packer to provide an annular seal ina wellbore. It is also often necessary to provide a physical link toacross the annular seal to an operable downhole tool or device. Forexample, it is often necessary to transmit electrical signals, opticalsignals, hydraulic pressure, and electrical energy across the annularseal.

SUMMARY

In view of the foregoing and other considerations, the present inventionrelates to extending a control line across a packer that set and formingan annular seal. Accordingly, examples of devices, systems, and methodsfor extending the control line across the annular seal provided by thepacker are provided.

An example of a packer for providing an annular seal when set in awellbore or tubular includes a tubular mandrel having an outer surface;a seal member having an inner surface defining a bore, the seal memberencircling a portion of the mandrel; and a control line positionedbetween the inner surface of the seal member and the outer surface ofthe mandrel and extending across the length of the seal member.

An example of a wellbore tool assembly includes a mandrel having anouter surface and a longitudinal bore; a tubular, swellable seal memberhaving opposing ends and an inner surface defining a bore between theopposing ends, the seal member encircling a portion of the mandrel; anoperable downhole element carried with the mandrel; and a control lineconnected to the operable downhole element, the control line extendingfrom the downhole element between the outer surface of the mandrel andthe inner surface of the seal member to the other side of the sealmember from the downhole element.

An example of a method for extending a control line across a packer setin a wellbore includes the steps positioning a control line along anouter surface of a tubular mandrel; encircling a portion of the tubularmandrel and the control line with a seal member, the control linepassing between the outer surface of the tubular mandrel and an innersurface of the seal member; and activating the seal member in a wellboreto form a seal between the outer surface of the tubular mandrel and asidewall of the wellbore.

The foregoing has outlined some of the features and technical advantagesof the present invention in order that the detailed description of theinvention that follows may be better understood. Additional features andadvantages of the invention will be described hereinafter which form thesubject of the claims of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features and aspects of the present inventionwill be best understood with reference to the following detaileddescription of a specific embodiment of the invention, when read inconjunction with the accompanying drawings, wherein:

FIG. 1 is a cross-section, elevation view of an example of a swellpacker of the present invention;

FIG. 2 is a cross-section view of an example of a swell packer of thepresent invention along the line I-I of FIG. 1;

FIG. 3 is a cross-section view of an example of a tool assembly of thepresent invention including a swell packer and a downhole element;

FIG. 4 is a schematic illustration an example of a packer of the presentinvention set in a wellbore; and

FIG. 5 is a cross-section view along the line II-II of FIG. 4.

DETAILED DESCRIPTION

Refer now to the drawings wherein depicted elements are not necessarilyshown to scale and wherein like or similar elements are designated bythe same reference numeral through the several views.

As used herein, the terms “up” and “down”; “upper” and “lower”; andother like terms indicating relative positions to a given point orelement are utilized to more clearly describe some elements. Commonly,these terms relate to a reference point as the surface from whichdrilling operations are initiated as being the top point and the totaldepth of the well being the lowest point.

Wellbore packers are utilized to form annular seals between the mandrelthat carries the seal member of the packer and a sidewall of a bore inwhich the packer is positioned. The outer sidewall may be an outertubular or the earthen formation in which the wellbore is formed.

Common types of packers include inflatable packers, mechanicalexpandable packers, and swell packers. Inflatable packers typicallycarry a bladder that may be pressurized to expand outwardly to form theannular seal. Mechanical expandable packers have a flexible materialexpanding against the outer casing or wall of the formation whencompressed in the axial direction of the well. Swell packers comprise asealing material that increases in volume and expands radially outwardwhen a particular fluid contacts the sealing material in the well. Forexample the sealing material may swell in response to exposure to ahydrocarbon fluid or to exposure to water in the well. The sealingmaterial may be constructed of a rubber compound or other suitableswellable material.

FIG. 1 is a cross-section, elevation view of an example of a swellpacker of the present invention generally noted by the numeral 10. Swellpacker 10 includes a mandrel 12, swellable seal member 14, and a controlline 16. The illustrated example provides anchors 18 positioned onopposing sides of seal member 14. Swell packer 10 is particularlyadapted for providing an annular seal in a wellbore.

Mandrel 12 may be a tubular member, such as a sub, or the like dedicatedas the base member of packer 10. For example, in a pre-fabricatedexample mandrel 12 may be a sub. Mandrel 10 may have opposing ends thatare adapted for connecting with other tools and or tubular joints. Insome installations, mandrel 12 may be a tubular joint that is connectedin a work string or that is to be connected into a work string. Forexample, it may be desired to provide a packer 10 at a well site bydisposing seal member 14 over a control line 16 and tubular joint asfurther described below.

Seal member 14 is a substantially tubular member having a bore 20extending between opposing ends 22, 24. Seal member 14 is formed of amaterial that swells when exposed to a particular fluid or condition.For example, seal member 14 may swell in volume in response to ahydrocarbon, water, or other activating fluid or chemical. Seal material14 may be formed of a rubber compound or other material. Seal member 14encircles mandrel 12 and is constructed as a unitary member. Member 14may be constructed of concentric layers and the layers may havedifferent modulus of elasticity and or different swellability from oneanother.

Various mechanisms and means may be utilized to connect seal member 14to mandrel 12. In FIG. 1, mechanisms 18 are positioned on opposing sidesof member 14 to hold member 14 at a desired location on mandrel 12.Mechanism 18 is defined generally herein as an anchor and may includevarious elements including end-rings that hold member 14 in a desiredposition and/or limit extrusion of member 14 when it is set in thewellbore, for example from differential pressure. Non-mechanical means,such as adhesives or bonding methods, of holding member 14 in positionmay also be utilized.

Mechanism 18 may comprise a radially swellable member. The radiallyswellable mechanism 18 may have a higher modulus of elasticity andtherefore be stiffer than seal member 14. As such, mechanism 18 may actto prevent or mitigate the extrusion of seal member 14 when it is set inthe wellbore. Swellable anchor mechanism 18 may include multiple discmembers each of which is swellable and that may have differentswellabilities and Young's modulus. Control line 16 may be passedbetween an inner surface of mechanism 18 and the outer surface ofmandrel 12.

Control line 16, as described further below, is positioned between sealmember 14 and mandrel 12 to provide communication between elements onopposing sides of packer 10. “Control line” is defined herein to includevarious mechanisms that may be utilized to communicate signals, or data,or energy across packer 10. Examples of control line 16 include withoutlimitation: cables of any type, including conductors and fiber optics;and conduits, such as tubing and the like for passing a pressurizedfluid such as hydraulic fluid. Control line 16 may be provided totransmit data, electronic signals, pressurized fluid, and/or electricalpower. For example, it may be desired to transmit an actuating signalfrom above packer 10 to a control valve on the other side of packer 10or to transmit data from a sensor positioned below packer 10 to thesurface.

FIG. 2 is a cross-section view of packer 10 along the line I-I ofFIG. 1. Packer 10 is illustrated in the un-set or unactivated positionprior to seal member 14 being activated to swell. Seal member 14 ispositioned about mandrel 12 and a gap 28 is formed between a portion ofthe inner surface 26 of seal member 14 and the outer surface 30 ofmandrel 12. Control line 16 is disposed in and through gap 28 such thatit extends past opposing ends 22, 24 (FIG. 1) of seal member 14. In thisexample control line 16 a is an electrical cable for providingelectrical power and control line 16 b is hydraulic line.

In the illustrated examples, control lines 16 are positioned betweeninner surface 26 of seal member 14 and outer surface 30 of mandrel 12.Control lines 16 are not positioned within a groove, slit or otherpassage formed in or through inner surface 26 of seal member 14. Gap 28is not formed by removing any material from seal member 14 but exists byseparating seal member 14 from mandrel 12. It is envisioned that forminga groove, slit or the like in seal member 14 may weaken the member orotherwise increase the incidence of failure in the wellbore.

Referring to FIGS. 1 and 2, packer 10 may be pre-fabricated forconnecting within a work string at the well site or other location. Bypre-fabricated it is meant that packer 10 is prepared for connectingwithin a tubular string at a well site, or other location, at a latertime. Terminal ends 32 may be blank, for splicing, or include a suitableconnector, for connecting with additional tools and/or the work stringcontrol line.

In other examples, control line 16 may be installed at the well site.For example, a control line 16 may be run along the outer surface ofmandrel 12 which may be a tubular joint. Mandrel 12 and control line 16may be inserted through bore 20 of seal member 14. When seal member 14is properly positioned it may be cemented in place and/or secured withanchor member 18. For example, in FIG. 2 a portion of inner surface 26of member 14 is cemented with an adhesive to outer surface 30 of mandrel12 at section 34.

FIG. 3 is a cross-section view of an example of a tool assemblygenerally denoted by the numeral 40. Tool assembly 40 includes a packer10 interconnected with an operable downhole element 42. Control line 16is shown extending across packer 10 and operationally connected todownhole element 42. In this example, control line 16 is shown extendingbeyond downhole element 42 for connecting to a subsequent downholeelement that is not shown. Downhole element 42 is referred to herein asoperable for purposes of describing that it is a device that utilizescontrol line 16 for at least a portion of its operational purpose.

Downhole element 42 may be any device, tool, or sensor to which controlline 16 is connected and is referred to herein as a valve for purposesof description. Packer 10 includes mandrel 12 and valve 42 includes amandrel 12 a which form a continuous longitudinal bore 44. In FIG. 3,mandrel 12 and mandrel 12 a are illustrated as separate membersinterconnected at seam 46. However, it should be recognized that mandrel12 and mandrel 12 a may be sections or portion of a continuous tubularjoint.

Tool assembly 40 may be prefabricated for later installation in a workstring, for example at a well site. One advantage of preassembled toolassembly 40 is the elimination of the requirement to splice or otherwiseconnect control line 16 between packer 10 and downhole element 42 at thewell site. Elimination of this step can reduce rig costs and mitigateone source of failure of a control system. Another advantage is thatcontrol line 16 is held close to tubular 12 and is thus protected duringshipping, handling, and well installation operations.

Refer now to FIG. 4, wherein an example of packer 10 is illustratedpositioned and set in a wellbore 36. Packer 10 is conveyed into andpositioned at a selected position within wellbore 36 on a tubularstring. Seal member 14 is set by contact with an activating agent thatcauses seal member 14 to swell. When activated, seal member 14 expandsradially outward from mandrel 12 and into sealing contact with asidewall 38. In this example sidewall 38 may be an earthen formation,casing, or any other tubular such as sand screen base pipe, liners andthe like. It is noted that packer 10 may be utilized as an open-holepacker or a cased-hole packer. It is envisioned that packer 10 promotesannular sealing in open-hole applications while facilitating the passingof control lines across the set packer.

FIG. 5 is a cross-section view along the line II-II of FIG. 4. FIG. 5illustrates seal member 14 in the set position. When seal member 14 isactivated it swells such that inner surface 26 closes against controlline 16 and mandrel 12 closing gap 28 (FIG. 2). A slight gap is shownaround control line 16 in FIG. 4 for purposes of illustration. However,it is envisioned that seal member 14 will seal or substantially sealabout control line 16 and mandrel 12.

From the foregoing detailed description of specific embodiments of theinvention, it should be apparent that novel devices, systems, andmethods for running a control line across a packer that is set in awellbore have been disclosed. Although specific embodiments of theinvention have been disclosed herein in some detail, this has been donesolely for the purposes of describing various features and aspects ofthe invention, and is not intended to be limiting with respect to thescope of the invention. It is contemplated that various substitutions,alterations, and/or modifications, including but not limited to thoseimplementation variations which may have been suggested herein, may bemade to the disclosed embodiments without departing from the spirit andscope of the invention as defined by the appended claims which follow.

1. A packer for providing an annular seal when set in a wellbore ortubular, the packer comprising: a tubular mandrel having an outersurface; a seal member having an inner surface defining a bore, the sealmember encircling a portion of the mandrel; and a control linepositioned between the inner surface of the seal member and the outersurface of the mandrel and extending across the length of the sealmember.
 2. The packer of claim 1, wherein the control line is notpositioned in a slot cut into the inner surface of the seal member. 3.The packer of claim 1, wherein the packer includes an anchor mechanismpositioned at each end of the seal member to position the seal member onthe mandrel.
 4. The packer of claim 3, wherein the anchor mechanismincludes a radially swellable material.
 5. The packer of claim 2,wherein the packer includes an anchor mechanism positioned at each endof the seal member to position the seal member on the mandrel.
 6. Thepacker of claim 5, wherein the anchor mechanism includes a radiallyswellable material.
 7. The packer of claim 1, wherein the seal member isconstructed of a swellable material that expands radially from themandrel upon contact with an activating agent.
 8. The packer of claim 7,wherein the seal member is a unitary member.
 9. The packer of claim 8,wherein the control line is not positioned in a slot cut into the innersurface of the seal member.
 10. The packer of claim 9, further includingan anchor mechanism positioned at each of the seal member, the anchormechanism constructed of a radially swellable member.
 11. The packer ofclaim 10, wherein the anchor mechanism has as a modulus of elasticitygreater than that of the seal member.
 12. The packer of claim 7, whereinthe control line is not positioned in a slot cut into the inner surfaceof the seal member.
 13. The packer of claim 12, wherein the seal memberis a unitary member.
 14. A wellbore tool assembly, the assemblycomprising: a mandrel having an outer surface and a longitudinal bore; atubular, swellable seal member having opposing ends and an inner surfacedefining a bore between the opposing ends, the seal member encircling aportion of the mandrel; an operable downhole element carried with themandrel; and a control line connected to the operable downhole element,the control line extending from the downhole element between the outersurface of the mandrel and the inner surface of the seal member to theother side of the seal member from the downhole element.
 15. Theassembly of claim 14, wherein the control line is not positioned in aslot cut into the inner surface of the seal member.
 16. The assembly ofclaim 14, wherein the downhole element is connected to a tubular that isconnected to the mandrel carrying the seal member.
 17. The assembly ofclaim 16, wherein the control line is not positioned in a slot cut intothe inner surface of the seal member.
 18. A method for extending acontrol line across a packer set in a wellbore, the method comprisingthe steps of: positioning a control line along an outer surface of atubular mandrel; encircling a portion of the tubular mandrel and thecontrol line with a seal member, the control line passing between theouter surface of the tubular mandrel and an inner surface of the sealmember; and activating the seal member in a wellbore to form a sealbetween the outer surface of the tubular mandrel and a sidewall of thewellbore.
 19. The method of claim 18, wherein the control line is notpositioned in a slot cut into the inner surface of the seal member. 20.The method of claim 18, wherein the step of activating includescontacting the seal member with an activating agent causing the sealmember to expand radially between the sidewall and the outer surface ofthe mandrel and substantially sealing about the control line.